Chandelure should be steel/fire (although ghost makes it heaps cooler)
Dodrio needs to not be flying type (if Psyduck and Empoleon aren't flying type neither should doduo/dodrio).
Gyarados should be plain water if you want go by the myth.
Many more later...
Totally agree with you on Flygon and Vibrava, if I were to glance at them I'd assume Bug before anything else.
How would Chandelure be a Steel/Fire? Its based of the Hitodama, a blue-black or purple fire associated with ghosts (Western equivalent is the will-o'-the'wisp), and a chandelier.
iirc Doduo and Dodrio have small wings according to Pokedex entries. But I get what you mean. (plus Golduck isn't flying because it doesn't have any physical features that would imply flying)
Gyara could be a plain Water, but Water/Flying fits its design ok. _ _ _ _ _ _
Braviary should be Fighting/Flying Drapion should be Dark/Bug instead of Dark/Poison Feraligatr should be part Fighting Samurott should be part Fighting Darkrai always struck me as a Dark/Ghost, when I saw it for the first time I was sure it was Dark/Ghost